31. In 1972, Mann came upon Miley's glass negatives at Washington and Lee University and has printed thousands of them. 32. Photographs This collection consists of about 3, 500 prints, glass negatives and carte-de-visit, plus 2, 190 lantern slides. 33. That same year, Henry Wellcome acquired a collection of glass negatives , totalling over 600, that were owned by Thomson. 34. Using glass negatives at this time, Leonard increased the sensitivity of the plates by exposing them to mercury vapor. 35. Pope was one of the first architectural students to master the use of the large-format camera, with glass negatives . 36. Among notable works in the archive are the Lunther Cody Collection of Glass Negatives , documenting classic life in New England. 37. For these images he often used glass negatives as these had short exposure times allowing a high level of detail. 38. The museum also houses the Paulus Collection of photograph glass negatives of the Salem area from the early Twentieth Century. 39. The glass negatives had to be developed in the darkroom at a later date and then printed as positive prints. 40. The musuem has the largest collection of Chansonetta prints in existence, many of her glass negatives , photo equipment and personal effects.
